Heating, ventilating, and air-conditioning (HVAC) systems and methods have been used to maintain desirable temperatures and humidity levels within buildings and buildings have been constructed with ventilation systems, including HVAC systems, to provide comfortable and safe environments for occupants to live and work and for equipment to operate. Air conditioning systems and methods have been used, for example, to cool data centers, clean rooms, spaces that contain swimming pools, and many other types of spaces having particular needs for cooling, dehumidification, or both. Chillers have been used to chill water that has been circulated to air handlers and used to cool air within the space. Water has also been used to transfer waste heat from chillers to a heat sink, such as a heat exchanger to outside air, cooling tower, or ground heat sink, as examples.
Examples of the prior art are described in U.S. Pat. Nos. 4,769,053, 5,573,058, 5,806,582, and 6,199,388, and International Patent Application publication number WO 94/14011, all of which are incorporated herein by reference in their entirety. Certain terms, however, may be used differently in the documents that are incorporated by reference, and if any conflicts, errors, or ambiguity exist, this document shall govern herein.
Chillers that produce chilled water have been used as an efficient way to provide cooling and dehumidification, particularly for large buildings, but opportunities for improvement exist in the use of chillers and water systems, particularly under certain circumstances. Needs and opportunities for improvement exist, for example, for providing systems and methods that cool more efficiently under certain circumstances, that require few or smaller components, that provide other benefits, or a combination thereof. Room for improvement exists over the prior art in these and various other areas that may be apparent to a person of ordinary skill in the art having studied this document.